Monthly Archives: October 2012

A Visit with Doug Smith

Posted on October 27, 2012 | Leave a comment

I’ve known Doug Smith for over 20 years and finally had chance to visit his new office and lab in Boulder City, NV, and interview him as I traveled out to the west coast for some other business. More…

Figure 1 – Doug at work in his new digs.

Leave a comment

Posted in General

Tagged

DIY ESD Detector

Posted on October 27, 2012 | Leave a comment

ESD detectors are useful in correlating unusual circuit upsets with specific ESD events. The following is based on a simple lightning detector circuit by Charles Wenzel and written up later by Bob Radmore in the April 2002 issue of QST Magazine. It was since improved by Wenzel and described on his Web site. It turns out this circuit also makes a great ESD detector. I took the original circuit, added an LED lamp, piezo beeper and LCD counter to record the number of ESD events. More…

Figure 1 – Low-cost DIY ESD detector based on a circuit for a lightning detector.

Leave a comment

Posted in Troubleshooting

Tagged ,

Upcoming EMC Seminars

Posted on October 12, 2012 | 1 comment

A couple times a year, I like to list a few educational opportunities available for us as a community. As a consultant and trainer in this area myself, I don’t mind mentioning others in this business, as well, because there are several very good resources from which to choose. more…

Figure 1 – Here I am teaching a 2-day seminar in Colorado. Most EMC seminars will be 2 to 3 days long and the best ones will include several demos of basic EMC principles, as well as detailed discussion of specific issues from the participants. Be sure to check in advance that the seminar content and level (basic or advanced) is really what you need before you commit.

1 Comment

Posted in Seminars

Tagged ,

Characterizing a Simple Dipole Antenna

Posted on October 12, 2012 | Leave a comment

As EMC engineers, we use many types of antennas – many broadband, these days. As a traveling EMC troubleshooter/consultant, I reply on small collapsible DIY antennas for troubleshooting, as described in an earlier blog posting.

In order to characterize these adjustable antennas versus frequency, it’s useful to be able to measure them with different element lengths extended, so that you know about where to set the length for the specific harmonics of interest. Using the new Rigol DSA815TG spectrum analyzer with tracking generator, and VSWR (voltage standing wave ratio) option, you can determine both the resonant frequency and VSWR, or how well the antenna is matched to the 50-Ohm coax cable. more…

Leave a comment

Posted in EMC Measurements, Troubleshooting

Tagged ,

ESD-Caused Fires

Posted on October 12, 2012 | Leave a comment

While cellphones have been disproven to cause gas pump fires, ESD-caused fires do occur at regular intervals – as many as several hundred times per year, according to the ESD Association. As we approach the winter season, where, typically, we get lower humidity levels, we need to be extra careful about ESD discharges when filling our gas tanks. As a pilot, we were always cautioned to connect the earth lead from the pump to metal structure on the plane prior to fueling for just this reason.

I’ll describe a couple real events. more…

Leave a comment

Posted in General

Tagged ,

New Low-NF Broad Band Preamp from Mini-Circuits

Posted on October 12, 2012 | Leave a comment

One of my favorite companies, Mini-Circuits, developed a (really!) low-noise, broad band, preamp (model PSA4-5043+) earlier this year for use as a front-end amplifier for mobile telecom applications, such as GSM, CDMA, LTE and WiMax. However, it would also be ideal to amplify spectrum analyzers and the low-noise feature would lower the effective noise figure of the analyzer, allowing you to see low-level signals better. This would not only be useful for amplifying near-field or current probe outputs, but would work well to boost the antenna output in semi-anechoic chambers – especially if there is a long run of coax cable.

Lets take a closer look and sweep the gain on our spectrum analyzer. more…

Leave a comment

Posted in EMC Measurements, Reviews

Tagged